Human Rights Watch has called on the international community to hold Uzbekistan to account over its violent crackdown in Andijan a year ago.

"The need for a co-ordinated and forceful international response to the Andijan massacre is more urgent than ever," said the US human rights group.

Although details remain unclear, it is thought hundreds of people may have been killed on 13 May last year.

The crackdown in Andijan town square followed an uprising and jailbreak.

The Uzbek president, Islam Karimov, has repeatedly rejected calls for an inquiry, insisting the demonstrators were armed Islamic militants.

"The Uzbek government has done nothing to hold the perpetrators of this atrocity accountable, and the international community has failed to compel the Uzbek authorities do so. The victims deserve no less than full justice," HRW executive director Kenneth Roth said on Thursday.

The group called on the EU and US to expand diplomatic and economic sanctions imposed on Uzbek leaders after the violence.

Climate of fear

HRW says Uzbek authorities have launched a "fierce crackdown" on political opponents, activists and journalists trying to investigate the events of 13 May 2005.

In the past year the BBC has been prevented from working freely in Uzbekistan.